I am rarely convinced by that cliched style of long-exposure photography that streaks the nighttime urban landscape with traces of fast-moving neon. Such images were popular in the 80s on the glossy cover of corporate brochures and teenage boys' bedroom posters. They are supposed to give the impression of movement and energy, of a booming modern economy, of the restlessness of the successful urban professional. But the thing about this photographic technique is that it turns people into blurred movements, almost into ghosts. Slowing down the shutter speed captures what is permanent but obscures what is transient. In the Elephant and Castle, London, that means we see the buildings and lose the faces. That's the wrong way round.

The Elephant is undeniably a place of transience. Millions travel through here at speed, often without ever noticing the people. Thousands of cyclists a day risk the hazards of its notoriously dangerous gyratory system, rightly concentrating on the road not the place. This is somewhere to get through, on the way to somewhere else. And this is not just true of commuters. For the Elephant has one of the most transitory populations of London. People come and go. Indeed, a photographer who could set the time exposure on his camera for a century or so would register almost nothing that has stayed the same. Even the buildings would be ghosts. The Nazi bombers saw to that.

Round here, change is the only constant. Nothing feels solid. The Elephant is continually and permanently liminal. An exhibition of photographs by Paul Reas called From a Distance, currently on display at the London College of Communication, emphasises a very different reality about the Elephant. Rescued from the anonymous blur of passing time and passing populations is the particularity of the human face and lived human experience. It's as if the photographer has simply stopped and noticed. In one sense, this seems like such a small thing. But the face is often the absent ingredient of morality. And those moral systems that try and do without it end up as dehumanising as the system built architecture for which the Elephant is known and all that can be recognised by the long-exposure image.

This idea of distance is one that Rowan Williams picks up on in a different but not unconnected example. "The terrorist, the suicide bomber, is someone who's got to the point where they can only see from a distance: the sort of distance from which you can't see a face, meet they eyes of someone, hear who they are, imagine who or what they love. All violence works with that sort of distance. It depends upon not seeing things."

'Break Up'. Photograph by Paul Reas

I am still a newcomer to the Elephant. I moved to here from the City of London, barely two miles away. From the great glass palaces of the City one can clearly see the Elephant, but from a distance. One can see but not see. Paul Reas schools us to look closer – surely the photographer's moral role. His images of incense pots, bought off the market, reveal something of the social pressures and hidden desperation. These pots are to be burned to provide help in specific situations. One pot is marked "break up", others "fast luck", "court case" Other images are of discarded chairs found on the streets. They invite you to reconstruct stores of families moving on. As he was completing this project, Reas' family house in Bradford was being compulsory purchased by the council to make way for redevelopment. It sensitised him to the experience of loss that accompanies change.

But the centre of the exhibition is the face – that which the philosopher Emmanuel Levinas described as the deepest origins of moral responsibility. It is, for me, the reason why utilitarianism, both moral and architectural, always fails. It has no understanding of particularity. It always sees from a distance.